Setting Up the Injector

For the fuel injection, you create an injector Engine Part, which provides a template for defining the geometry and the physics of the injector and its nozzles.

To create the injector:
  1. Right-click the Engine node and select Create Injector.
    The Edit tab opens and displays the injector template. The Graphics window updates and displays an injector with a single solid-cone nozzle. By default, the injector is centered in the cylinder head and aligned with the cylinder axis.
  2. In the Graphics window, change the view to obtain a similar engine position to the one shown below:


To position the injector:
  1. Within the Edit dialog, in the Geometry tab, set the following properties:
    Property Setting
    Injector Origin [X, Y, Z] [8.0 mm, 0.0 m, 10.0 mm]
    Injector Direction [X, Y, Z] [-1.0 mm, 0.0 m, -2.4 mm]
  2. To preview the injector in the Graphics window, click Update at the bottom of the dialog.
    Simcenter STAR-CCM+ In-cylinder updates the placement of the injector:


The default nozzle of the injector is oriented along the x-axis of the injector coordinate system. For a multi-nozzle injector, you use this nozzle as reference nozzle. Simcenter STAR-CCM+ In-cylinder automatically duplicates this nozzle and equally distributes the duplicates around the injector axis.

To set up the nozzles:

  1. For the reference nozzle, set the following properties:
    Property Setting
    Nozzle Origin Reference [X, Y, Z] [1.0 mm, 0.0 m, 1.0 mm]
    Nozzle Target Reference [X, Y, Z] [10.0 mm, 0.0 m, 17.0 mm]
  2. Click Update.
    Simcenter STAR-CCM+ In-cylinder updates the position and orientation of the nozzle as displayed below:


  3. Set Number of Nozzles to 6, then click Update.
    Simcenter STAR-CCM+ In-cylinder creates five duplicates of the reference nozzle and distributes them around the injector axis. The angular distance between the nozzles is given by α=360⁢  deg⁡⁢  Number⁢  of⁢   Nozzles=60⁢deg⁡. To avoid that nozzles are positioned on the symmetry plane, Simcenter STAR-CCM+ In-cylinder automatically applies a Nozzle Rotation Offset of αrot=⁡α2=30⁢deg⁡.

    The following image displays the three nozzles that coincide with the fluid domain:



To set the hydraulic diameter of each nozzle hole:
  1. In the Per Nozzle group box, set Hydraulic Diameter to 0.2 mm, then click Update.
To set up the injection conditions:
  1. Click the Physics tab.
  2. Set the mass flow rate using tabular data:
    1. Below the Mass Flow Rate property, next to the File drop-down menu, click Import.
    2. In the Import Table dialog, navigate to the inCylinder folder of the downloaded tutorial files.
    3. Select injector_MassFlowRate.csv and click Open.
      The imported table describes the mass flow rate as a function of crank angle for the full injector. For a half engine model with an injector positioned on the symmetry plane, Simcenter STAR-CCM+ In-cylinder calculates the mass flow rates for the nozzles within the half model accordingly.
    4. Set Mass Flow Rate Units to kg/s.
    The plot in the Graphics window displays the mass flow rate as a function of crank angle for the full injector:


  3. Set tabular data for the fuel temperature:
    1. Set Fuel Temperature to Table.
    2. Import the file injector_Temperature.csv using the same procedure as described for the mass flow rate table.
    The plot below displays the fuel temperature curve:


  4. Set the droplet diameter distribution using a CDF table:
    1. Set Droplet Diameter to CDF Table.
    2. Import the file injector_DropletDiameterCDF.csv
    The following plot displays the cumulative distribution function for the particle diameter:


  5. Click Update, then OK.
  6. Save the simulation .